Worked great on my AV Famicom
They WORK as intended. Both of them. The NES one is perfect. The SNES one is pretty good. He had the sense to bind A and B to B and Y on the SNES controller like Super Mario World and all the good platformers did instead of this literal A and B mapping NONSENSE. Only way this could be better is if the A and B buttons were literal but X would register as B as well (similar to Switch online's NES button scheme). Or to have infinite beer. One or the other Im down.
I got a Sharp Twin Famicom recently for two reasons: first was that I wanted a way to play FDS games, and second was that I found out about the NES controller adapter available here!
My favorite part is having the option to not sit a few feet from my CRT with the hardwired controllers. The icing on the cake for me was that I didn't need to sacrifice Zapper compatibility when moving over from a frontloader NES. With a 72-to-60 pin cart converter, I can play all my NES Zapper games on my Twin issue-free.
The adapter's build quality is much better than anything I could have made myself by cutting up controller extension cables. Very glad with my purchase.
I purchased the NES and SNES adapters, and I could not be happier! The adapters work with every US NES and SNES controller I own, including 8BitDo wireless 2.4g controllers like the N30 and SN30. For those interested in an affordable alternative to the Video Shooting Series Light Gun for the Famicom, the NES adapter allows your Zapper to work on the OG and Twin Sharp consoles. Playing Famicom/NES games with a Super Famicom ASCIIPad is quite nice as well. This is an excellent, inexpensive way to diversify the ways you can play your Famicom. Worth it!
Original Hardware Controller Adapters